Heat exchanger construction and method for making the same



Dec. 27, 1966 H. J. LOEHLEIN ETAL 3,294,162

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME 8 Sheets-Sheet 1 Filed Dec. 23, 1963 INVENTORS HAROLD J.LOEHLE|N EDWARD E. CURRAN BY I w M/fl THEIR ATTORNEYS Dec. 27, 1966 H. J. LOEHLEIN ETAL 3,294,162

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME 8 Sheets-Sheet 2 Filed Dec. 23, 1963 FIG.7

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INVENTORS HAROLD J.LOEHLE|N EDWARD E..CURRAN BY m 640? 1 THEIR ATTORNEYS Dec. 27, 1966 H. J. LOEHLEIN ETAL 7 3,294,162-

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME Filed Dec. 23 1963 8 Sheets-Sheet 5 INVENTORS HAROLD J. LOEHLEIN EDWARD E. GURRAN BY a n 4%, uzziw THEIR ATTORNEYS 1966 H. J. LOEHLEIN ETAL 3,

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME 8 Sheets-Sheet Filed Dec. 23, 1963 INVENTORS HAROLD J.LOEHLEIN EDWARD E.CURRAN BY 5 Z hmw THEIR ATTORNEYS 1966 H. J. LOEHLEIN ETAL 3,

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME 8 Sheets-Sheet 5 Filed Dec.

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INVENTORS F I HAROLD J.LOEHLEIN EDWARD E.CURRAN BY km THEIR ATTORNEYS H. J. LOEHLEIN ETAL Dec. 27, 1966 HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME 8 Sheets-Sheet 6 Filed Dec. 23, 1963 FIG.I9

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INVENTORS HAROLD J-LOEHLEIN EDWARD ECURRAN BY M %W/ THEIR ATTORNEYS 1966 H. J. LOEIHLEJN ETAL 3,

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE] SAME Filed Dec. 23, 1963 8 Sheets- Sheet 7 F l G. I NVENTORS HAROLD J.LOEHLEIN EDWARD E. GURRAN THEIR ATTORNEYS 1966 H. J. LOEHLEIN ETAL 3,294,162

HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME Filed Dec. 23, 1963 8 Sheets-Sheet 8 INVENTORS HAROLD J. LOEHLEIN EDWARD E. GURRAN THEIR ATTORNEYS United States Patent 3,294,162 HEAT EXCHANGER CONSTRUCTION AND METHOD FOR MAKING THE SAME Harold J. Loehlein, Henrico County, Va., and Edward E. Curran, Louisville, Ky., assignors to Reynolds Metals Company, Richmond, Va., a corporation of Delaware Filed Dec. 23, 1963, Ser. No. 332,818 19 Claims. (Cl. 165-181) This invention relates to an improved heat exchanger construction or the like as well as to improved methods and apparatus for making such a heat exchanger construction or the like.

It is well known that heat exchangers can be formed of a hollow tubular member through which a cooling or heating medium is circulated whereby the outer peripheral wall of the hollow tubular member forms the primary heat exchanger surface for heat transfer purposes.

In order'to increase the heat transfer between the surrounding atmosphere and the circulating medium, various manufacturers provide fin means to beattached to the outer peripheral surface of the hollow tubular member to increase the surface area of the heat exchanger structure, the fins each forming what is commonly known as a secondary heat exchanger surface.

However, it has been found that the fins forming the secondary heat exchanger surfaces of the heat exchanger must be intimately placed in contact with the primary heat exchanger surface in order for the same to be effective whereby many manufacturing problems are encountered.

According to the teachings of this invention, such secondary heat exchanger surface is uniquely provided whereby the secondary heat exchanger surface is formed integrally with the primary heat exchanger surface in such a manner that an effective heat exchanger construction is provided.

In particular 1 me pe of heat exchanger structure of this invention 1; provided by extruding a hollow tubular member from tallic material, such as aluminum-containing metallic aterial or the like, with the hollow tubular member having an outwardly directed flange integrally interconnected thereto and substantially radiating from the longitudinal axis of the hollow tubular member.

Thereafter, the flange of the hollow tubular member is divided into a plurality of fins each having its surface area substantially increased over the surface area of the part of the flange from which therespective fin has been formed whereby an effective heat exchanger construction is provided in a rapid and simple manner.

As will be apparent hereinafter, the heat exchanger construction of this invention can be utilized in many applications for the transfer of heat in a simple and effective manner heretofore unobtainable by well known heat exchanger constructions whereby the heat exchanger constructions of this invention are relatively inexpensive.

Accordingly, it is an object of this invention to provide an improved heat exchanger construction having one or more of the novel features of this invention as set forth above or hereinafter shown or described.

Another object of this invention is to provide an improved method for making such a heat exchanger construction or the like.

A further object of this invention is to provide an improved apparatus for making such a heat exchanger construction or the like.

Other objects, uses and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawings forming a part thereof and wherein:

FIGURE 1 is a perspective view illustrating one embodiment of the heat exchanger blank of this invention.

FIGURE .2 is a view similar to FIGURE 1 and illustrates another embodiment of the heat exchanger blank of this invention.

FIGURE 3 is a schematic, fragmentary, perspective view illustrating the method and apparatus for converting the blank of FIGURE 1 or 2 into the heat exchanger construction of this invention.

FIGURE 4 is an end view of the method and apparatus illustrated in FIGURE 3.

FIGURE 5 is a front view of one of the gear means of the apparatus of this invention.

FIGURE 6 is a cross-sectional view taken on lines 66 of FIGURE 5.

FIGURE 7 is a fragmentary, cross-sectional view take-n on line 77 of FIGURE 6.

FIGURE 8 is a fragmentary, end view illustratinghow the apparatus of FIGURE 3 forms the heat exchanger construction of this invention.

FIGURE 9 is a top view of the heat exchanger construction of this invention.

FIGURE 10 is a side view of the heat exchanger construction illustrated in FIGURE 9.

FIGURE 11 is a fragmentary, cross-sectional view taken on line 11-11 of FIGURE 10.

FIGURE 12 is a top plan vie-w of an improved heat exchanger construction formed according to the teachings of this invention.

FIGURE 13 is a fragmentary, cross-sectional view taken on line 13-13 of FIGURE 12.

FIGURE 14 is a fragmentary, cross-sectional view taken on line 1414 of FIGURE 13.

FIGURE 15 is a view similar to FIGURE 14 and il lustrates the frame member of this invention before the same has been attached to the heat exchanger tube construction.

FIGURE 16 is a top plan view of another heat exchanger construction of this invention.

FIGURE 17 is a fragmentary, cross-sectional view taken on line-17-17 of FIGURE 16. I

FIGURE 18 is a fragmentary, cross-sectional view illustrating one application of the heat exchanger construction of this invention. I v 1 FIGURE 19 is a cross-sectional view taken on line 19-19 of FIGURE 18.

FIGURE 20 is a fragmentary, cross-sectional view of the heat exchanger tube construction of this invention.

FIGURE 21 is a plan view of a house or the like.

FIGURE 22 is a fragmentary, enlarged, cross-sectional perspective view taken on line 2222 of FIGURE 21.

FIGURE 23 is a cross-sectional view illustrating the heat exchanger construction of this invention in anothe application thereof.

FIGURE 24 is a cross-sectional view taken on line 2424 of FIGURE 23.

FIGURE 25 is a cross-sectional view of a domestic refrigerator or the like utilizing a heat exchanger construction of this invention.

FIGURE 26 illustrates another embodiment of this invention which can be utilized in the refrigerator of FIG- URE 25.

FIGURE 27 is an exploded perspective view of the parts illustrated in FIGURE 26. I

FIGURE 28 illustrates another application of the heat exchanger construction of this invention.

FIGURE 29 is a cross-sectional view illustrating another application of the heat exchanger construction of this invention.

FIGURE 30 is a perspective schematic view of the structure illustrated in FIGURE 29.

FIGURE 31 is a fragmentary perspective view -of an-,

other heat exchanger construction of this invention.

FIGURES 32 and 33 are views similar to FIGURE 31 and illustrate other embodiments of this invention.

FIGURE 34 is a view similar to FIGURE 8 and illustrates another embodiment of this invention.

While the various features of this invention are hereinafter described and illustrated as being particularly adaptable for forming a heat exchanger construction or the like, it is to be understood that the various features of this invention can be utilized singly or in any combination thereof to provide other constructions as desired. Therefore, this invention is not to be limited only to the embodiments illustrated in the drawings, because the drawings are merely utilized to illustrate one of the wide variety of uses of this invention.

Referring now to FIGURE 1, the improved heat exchanger blank of this invention is generally indicated by the reference numeral 40 and comprises an elongated hollow tubular member 41 having one or more outwardly directed flanges 42 integrally interconnected to the outer peripheral surface 43 of the hollow tubular member 41.

While the heat exchanger blank 40 of this invention can be formed in any suitable manner and of any suitable material, the embodiment illustrated in FIGURE 1 is formed by extruding metallic material, such as aluminum-containing metallic material or the like, by a conventional extruding apparatus 44 in a conventional man- Thus, it can be seen that the heat exchanger blank 40 of this invention can be extruded in a simple and effective manner to provide a heat exchanger having the desired length in a manner hereinafter set forth.

Further, while the heat exchanger blank 40 of this invention can have any suitable dimensions, the embodiment thereof illustrated in the drawing has the outside diameter of the hollow tubular member 41 approximately of an inch while the thickness of each flange 42 is approximately 0.035 of an inch, the width of the flanges 42 being any desired width.

However, it is to be understood that the above dimensions and materials for forming the heat exchanger blank 40 of this invention are not a limitation on this invention as the same can vary as desired.

While the flanges 42 of the heat exchanger blank 40 of this invention are of uniform thickness throughout the length thereof, it is to be understood that the same can have a varying thickness throughout the length thereof, if desired.

For example, reference is made to FIGURE 2 wherein another heat exchanger blank is generally indicated by the reference numeral 40A and parts thereof similar to the heat exchanger blank 40 are indicated by like reference numerals followed by the reference letter A.

As illustrated in FIGURE 2, the flanges 42A extending 'outwardly from the hollow tubular member 41A respectively taper from the outer peripheral surface 43A of the hollow tubular member 41A to the outer free edges of the flanges 42A.

For example, should the outer tubular member 41A have an outside diameter of approximately of an inch,

the flanges 42 can be approximately 0.035 inch at the outer peripheral surface 43A of the hollow tubular member 41A and tapered downwardly to approximately 0.020 inch at the outer free ends thereof.

Therefore, it can be seen that the heat exchanger blanks 40 and 40A of this invention can vary in the configuration thereof while still being adapted to form the heat exchanger constructions of this invention in a manner hereinafter set forth.

Therefore, since either the heat exchanger blank 40 or heat exchanger blank 40A can be utilized in the manner hereinafter described, only the heat exchanger blank 40 will be specifically referred to with the understanding be- 4 ing that the same description would apply to the heat exchanger blank 40A, if desired.

While the heat exchanger blanks 40 and 40A of this invention respectively have two diametrically opposed flanges 42 extending from the tubular member 41 or 41A, it is to be understood that the various features of this invention can be utilized with the hollow tubular member 41 or 41A having one or any desired number of flanges 42 disposed in any desired relationship about the outer peripheral surface 43 or 43A thereof whereby this invention is not to be limited to a heat exchanger construction having just two flanges 42 or 42A as Will be apparent hereinafter.

After the blank 40 has been formed in the above manner, the same has the flanges 42 thereof divided into a plurality of fins integrally interconnected to the hollow tubular member 41 to provide a unique secondary heat exchanger surface for the hollow tubular member 41, the fins each being formed from the flanges 42 and having the surface area thereof substantially increased over the part of the flange 42 from which the respective fin is formed in the manner now to be described.

Reference is now made to FIGURE 3 wherein an improved method and apparatus of this invention is generally indicated by the reference numeral 45 and is utilized to form the flanges 42 of the hollow tubular member 41 into a plurality of heat exchanger fins 46 integrally interconnected to the hollow tubular member 41 to provide a secondary heat exchanger surface therefor, each end 46 being formed from a part of the flange 42 and having the surface area thereof substantially increased over the original surface area of the part of the flange 42 from which the respective fin 46 is formed.

While the apparatus 45 illustrated in FIGURE 3 indicates that only one flange means 42 of the hollow tubular member 41 is being converted into fins 46, it is to be understood that the apparatus 45 of this invention can simultaneously form the fins 46 from the opposed flanges 42 of the hollow tubular member 41 in the manner illustrated in FIGURE 4.

The apparatus 45 comprises a pair of gear means 47 and 48 cooperating in a manner hereinafter described to operate on one flange means 42 of thehollow tubular member 41 and to rapidly and effectively convert the flange means 42 into the plurality of fins 46 in the manner illustrated in FIGURE 8 and which will be hereinafter described.

As illustrated in FIGURES 5-7, each gear means 47 and 48 is substantially identical to each other except that the gear means 47 has the teeth thereof pointing in one direction as illustrated in FIGURE 8 while the like teeth on the gear means 48 point in the opposite direction as illustrated in FIGURE 8 to perform the function of this invention.

Therefore, only the gear means 48 will be described and illustrated in FIGURES 5-7 with the'understanding that the gear means 47 is formed in the same manner except that the teeth thereof point in the opposite direction.

As illustrated in FIGURES 5-7 the gear means 48 includes a hub 49 having a cylindrical bore 50 passing therethrough to permit the gear means 48 to be fastened onto a suitable shaft by threaded members passing through threaded bores 51 formed in the hub 49.

The hub 49 of the gear means 48 has a plurality of teeth 52 radiating outwardly therefrom with each tooth 52 having a substantially arcuate leading surface 53 when the gear means 48 rotates in a clockwise manner in'FIGURE 5 while the trailing side 54 of the tooth 52 is substantially straight as illustrated in FIGURE 5.

As illustrated in FIGURE 8, each tooth 52 of the gear means 48 has a substantially flat outer end 55 which cooperates with the straight side 54 thereof to define a shearing edge 56 for a purpose hereinafter described. The leading side 53 of each tooth 52 of the gear wheel 48 curves arcuately from the point 57 to approximately the point 58 whereby the remainder of the surface 53 is substantially straight and parallel to the surface 54 until the surface 53 joins the hub 49 of the gear means 48.

As illustrated in FIGURE 6, each tooth 52 of the gear means 48 has a front side 59 which will be disposed adjacent the hollow tubular member 41 while the opposed side 60 of the tooth 52 will be remote from the hollow tubular member 41. The side 59 of each tooth 52 of the gear means 48 is arcuate in the manner illustrated in FIGURE 6 while the side 60 thereof is substantially straight.

Further each tooth 52 of the gear means 48 at the side 59 thereof is rounded or arcuate in the manner illustrated in FIGURE 7.

This particular configuration of the teeth 52 of the gear means 47 and 48 form the fins 46 from the flange 42 of the hollow tubular member 41 in a unique manner now to be described.

As illustrated in FIGURE 8, the gear means 47 is rotating in a counterclockwise direction while the gear means 48 is rotating in a clockwise direction so that the teeth 52 thereof mesh in the manner illustrated in FIG- URE 8, the flange 42 of the hollow tubular member 41 either being passed through the nip of the rotating gear means 47 and 48 from left to right in the manner illustrated in FIGURE 8 or the gear means 47 and 48 can be moved from right to left while the hollow tubular member 41 is being held stationary even though the gear means 47 and 48 are rotating in the manner indicated by the arrows in FIGURE 8.

In any event, it can be seen that as the gear means 47 and 48 rotate, the teeth 52 on the gear means 47 begin to bend the flange 42 of the hollow tubular member 41 downwardly as represented by the gear teeth 52a and 52b in FIGURE 8. However, since the teeth 52a and 5211 are arcuate at the surface 59 thereof as illustrated in FIGURE 6, the portion of the flange 42 adjacent the hollow tubular member 41 is not bent downwardly as illustrated in FIGURE 8.

As the tooth 52c of the gear means 48 begins to move upwardly between the teeth 52b and 52d of the gear means 47 in the manner illustrated in FIGURE 8, it can be seen that the tooth 52c begins to move the flange 42 upwardly between the teeth 52b and 52d while utilizing the edge 56 thereof to cooperate with the edge 56 and surface 54 of the gear tooth 52b to shear the flange 42 into a particular fin 46a.

As the gears 47 and 48 continue to rotate, it can be seen that the lower portion of each sheared fin 46 is drawn and ironed by the cooperating surfaces 53 on the adjacent teeth 52 of the gear means 47 and 48.

For example, it can be seen that the teeth 52c and 52 in FIGURE 8 are drawing and ironing the lower portion of the fin 46b to substantially elongate the same while the end 55 of the tooth 522 is moving the upper portion of the fin 46b back to a coplanar relation with the point of attachment of the fin 46b to the hollow tubular member 41.

As the gear teeth 52 of the gear means 47 and 48 pass through their fully meshed relation, it can be seen that the surfaces 53 of adjacent teeth 52 thereof cooperate together to draw and iron the top portion of each fin 46 to further elongate and substantially curve the same whereby the resulting fin 46 has a substantially S-shaped cross-sectional configuration.

For example, see FIGURE 8 wherein the gear teeth 52g and 52h of the gear means 48 and 47 respectively begin to draw and iron the top portion of the fin 460.

Thus, it can be seen that as the flange 42 of the hollow tubular member 41 is passed through the nip of the meshing gear means 47 and 48, the teeth 52 on the gear means 47 and 48 cooperate together to shear and divide the flange 42 into individual fins 46 while at the same time drawing and ironing the fins 46 to substantially increase the surface areas thereof over the surface areas of the parts of the flange 42 from which the respective fins 46 are formed whereby the fins 46 provide an effective secondary heat exchanger surface for the resulting heat exchanger construction 60 illustrated in FIGURE 9.

As previously set forth, the apparatus 45 of this invention can comprise merely a pair of gear means 47 and 48 which will operate on a single flange 42 of the hollow tubular member 41 or can comprise four gear means as illustrated in FIGURE 4 for simultaneously operating on the opposed flange means 42 of the hollow tubular member 41 to form the heat exchanger construction 60.

In any event, the gear means of the apparatus 45 of this invention so form the fins 46 in the manner illustrated in FIGURES 9-11 that each fin 46 is integrally joined to the outer peripheral surface 43 of the hollow tubular member 41 by opposed gusset shaped portions 61 and 62 as illustrated in the top view of FIGURE 9 to not only increase the strength or the particular fin 46 but to increase the surface contact thereof with the hollow tubular member 41 to promote the heat transfer in a manner well known in the heat exchanger art.

Such gusset portions 61 and 62 for each fin 46 are formed by having the leading surfaces 59 of the teeth 52 of the gear means 47 and 48 formed arcuately in the manner illustrated in FIGURE 7.

Further, each fin 46 has an inner portion 63 as illustrated in FIGURES 10 and 11 that curves arcuately and is joined to the remainder of the flange 42 to provide not only a structural relationship therewith, but also to increase the surface contact between the particular fin 46 and the outer peripheral surface 43 of the hollow tubular member 41.

Thus, it can be seen that the apparatus and method of this invention as illustrated in FIGURE 5 effectively divide the flange or flanges 42 of the hollow tubular member 41 into secondary heat exchanger surfaces comprising a plurality of fins 46 each having a surface area substantially increased over the surface area of the part of the flange 42 from which the respective fin 46 was formed.

For example, it has been found that the surface area of each fin 46 can be increased from at least 20% to over of the original surface area of the part of the flange 42 from which the respective fin 46 has been formed.

Thus, not only has the surface area of the fins 46 been increased in the above manner, but also the fins 46 are integrally interconnected to the outer peripheral surface 43 of the outer tubular member 41 whereby the most intimate contact is provided between the fins 46 and the hollow tubular member 41 to provide the heat transfer relationship required in a heat exchanger construction.

In addition, the fins 46 are so joined to the hollow tubular member 41 that the same are structurally attached thereto even though the same have been rendered relatively thin by the previously described drawing and ironing operation.

Thus, the apparatus and method of this invention effectively and simply form the heat exchanger construction 60 of this invention wherein the heat exchanger construction 60 has the advantages previously set forth.

After the desired length of the heat exchanger blank 40 has been formed into the heat exchanger construction 60, the heat exchanger construction 60 can be bent, coiled, spiraled, or remain straight for storage and shipment thereof for being formed into a particular configuration for a particular application thereof, the heat exchanger construction 60 of this invention being readily adaptable for most applications wherein a heat exchanger construction is needed.

For example, the heat exchanger construction 60 previously described can be sinuously bent in the manner .illustrated in FIGURES 12-15 to form another type of heat exchanger construction of this invention which is generally indicated by the reference numeral 64, the heat exchanger construction 64 being particularly adaptable as being utilized as an evaporator or condenser, as desired.

As illustrated in FIGURE 12, the heat exchanger construction 60 has been bent in a sinuous manner so that the same defines a substantially rectangular construction having elbows 65 at the opposed side of the rectangular construction and interconnecting together adjacent straight lengths 66 of the hollow tubular member 41, the hollow tubular member 41 being provided with its own inlet 67 and outlet 68 as illustrated in FIGURE 12.

If desired, the fins 46 on the hollow tubular member 41 can be removed in the region of the elbows 65 thereof as well as on the inlet 67 and outlet 68 thereof as illustrated in FIGURE 12.

In order to provide a rigid mounting construction for the sinuously bent tubular member 41, a pair of opposed frame members 69 are provided at the elbows 65 of the hollow tubular members 41 and attached thereto in a manner now to be described.

For example, each frame member 69 can comprise a lower portion 70 and an upper portion 71 defining a plurality of slots 72 therebetween which respectively receive the elbows 65 in the manner illustrated in FIG- URE 15.

Therefore, it can be seen that each frame member 69 can be slipped onto the elbows 65 at one of the opposed sides of the sinuously bent hollow tubular member 41 with the elbows 65 being readily received and passing through the slots 72 therein.

Thereafter, the upper portions 71 of the frame member 69 are deformed downwardly in the manner illustrated in FIGURES 13 ano 14 effectively interlock the elbows 65 thereto without utilizing fastening members or the like whereby the frame members 69 provide a rigid unit with the hollow tubular member 41 and permit the same to be readily mounted in any desired relationship by mounting means 73 on the frame members 69.

Another type of heat exchanger construction of this invention can be formed from the structure 60 illustrated in FIGURE 9 to provide an evaporator, condenser or the like in a manner similar to the heat exchanger construction 64 previously described, reference being made to FIGURES 16 and 17 wherein another heat exchanger construction of this invention is generally indicated by the reference numeral 74.

As illustrated in FIGURES 16 and 17, the hollow tubular member 41 previously described is sinuously and substantially spirally wound or coiled in the manner illustrated in FIGURE 16 to define a substantially rectangular construction having elbows 75 at the opposed sides thereof and respectively interconnecting together adjacent lengths 76 and 77 of the hollow tubular member 41, the hollow tubular member 41 having an inlet 78 and outlet 7 9 at the opposed ends thereof.

The coiled tubular member 41 is adapted to be formed into a rigid unit by a pair of opposed frame members 80 respectively interconnected to the elbows 75 of the bent tubular member 41.

For example, each frame member 80 can comprise substantially U-shaped portion 81 in the manner illustrated in FIGURE 17 disposed against the outside of each elbow 75 at one side of the rectangular construction and a substantially cylindrical bar or portion 82 respectively passing through the elbows 75 in the manner illustrated in FIGURE 17 and detachably secured to the portion 31 by a plurality of threaded fastening members 83.

Thus, it can be seen that in the heat exchanger construction 74 illustrated in FIGURES 16 and 17, the fins 46 on the hollow tubular member 41 need not be removed in the region of the elbow 75 thereof, if desired, as the portions 82 of the frame members efifectively interconnect the frame members 80 to the elbows 75, the inlet 78 and outlet 79 of the hollow tubular member passing effectively through suitable apertures formed in the portion 81 thereof as illustrated.

Therefore, it can be seen that unique heat exchanger constructions can be provided from the finned tubular member 41 of this invention to provide the desired heat exchanger function.

While the heat exchanger constructions 64 and 74 of this invention are particularly adaptable for forming evaporators or condensers for refrigerating systems or the like, it is to be understood that the same can be utilized in other places where heat exchanger structures are required.

For example, reference is made to FIGURE 25 wherein a domestic refrigerator 84 is provided and has the conventional non-frozen food compartment 85 and the conventional frozen food compartment 86 respectively cooled by an evaporator 87 having air forced across the same by a suitable fan 88. Thus, the heat exchanger constructions 64 and 74- of this invention are particularly adaptable for forming the heat exchanger construction 87 illustrated in FIGURE 25.

Thus, it can be seen that the finned tubular member 41 of this invention has many uses in the heat exchanger field and the same lends itself to particular configurations for particular heat exchanger applications.

For example, reference is made to FIGURE 18 wherein the finned tube 41 of this invention is disposed in spiral form that diminishes from left to right and is disposed in an air duct 89 through which air is forced from left to right.

If desired, the spiral configuration of the finned tube 41 in FIGURE 18 can be reversed so that the smaller end thereof is first contacted by the flow of air through the duct 89 from the left.

Because of the simplicity of the construction of the finned tube 41 of this invention, it can be readily seen in FIGURES 18 and 19 that the same is readily adaptable to be formed in spiral form for the intended purpose thereof.

Instead of circulating a cooling medium through the finned tube 41 of this invention in the manner previously set forth, it is to be understood that the same could have a resistance wire 90 passed therethrough in the manner illustrated in FIGURE 20 which will be insulated from the interior wall of the hollow tubular member 41 by magnesium oxide 91 or the like in a conventional manner whereby. the finned tube 41 can perform its heat exchanger function with the electrical heater element 90 in a conventional manner.

For example, such an electrical heat exchanger element as illustrated in FIGURE 20 can be utilized as a baseboard heater for a home or building 92 illustrated in FIG- URE 21 and having a baseboard 93 extending throughout the internal outer periphery thereof, the baseboard 93 comprising a conduit structure in the manner illustrated in FIGURE 22 whereby the finned tube 41 of this invention can pass through the baseboard 93 and be supported therein by suitable brackets 94.

In this manner, either a circulating heating medium can be passed through the hollow tubular member 41 in the baseboard 93 or the resistance wire 90 can be passed therethrough whereby the finned tube 41 of this invention will provide effective heating for the house or building 92, 111 a manner conventional in the art.

If desired, the finned tubular member 41 of this invention can be coiled upon itself in spiral fashion to provide a substantially flat heat exchanger construction for forming a condenser, evaporator, or the like for space heaters, air conditioning units, dehumidifiers and the like.

For example, reference is made to FIGURES 23 and 24 of this invention wherein a space heater is generally indicated by the reference numeral 95 and has the finned tubular member 41 thereof coiled upon itself to provide a heat exchanger through which air can be forced by a suitable fan 96 in a conventional manner, the finned tube 41 either having the desired medium circulated therethrough or having a resistance wire therein in the manner previously described.

If desired, the finned tube 41 of this invention can be disposed in substantially coiled cylindrical form in the manner illustrated in FIGURES 26 and 27 and placed in a suitable housing 97 to have air forced therethrough by a suitable fan 98, the coiled fin tube 41 of FIGURES 26 and 27 being particularly adaptable for domestic refrigerator use or the like although the same can be utilized in other places where a heat exchanger is desired.

Also, the finned tube 41 of this invention can be interconnected to an accumulator 99 in the manner illustrated in FIGURE 28 and be coiled about the accumulator 99 to provide means for transferring heat between the finned tube 41 and the accumulator 99.

In addition, the finned tube 41 of this invention can be utilized in an air conditioning unit or the like in the manner illustrated in FIGURES 29 and 30 whereby the finned tube is coiled to form an evaporator 100 and a condenser 101, the outlet of the condenser 101 being interconnected to the inlet of the evaporator 100 by a suitable capillary arrangement 102 while the outlet of the evaporator 100 is interconnected to a condenser 103 having the outlet thereof interconnected to the inlet of the condenser 101, suitable fans 104 and 105 being utilized to respectively direct air across the evaporator 100 and condenser 101.

Therefore, it can be seen that the finned tube 41 of this invention can be formed in a plurality of different shapes to form heat exchanger structures for particular applications thereof because the finned construction 41 of this invention is readily adaptable to be shaped in the desired configuration and can be simply and rapidly formed in the manner previously described whereby the overall cost of the heat exchanger constructions of this invention are relatively small when compared with prior known heat exchanger constructions.

In addition, the heat exchanger constructions of this invention have the specific advantage of the intimate contact between the primary and secondary surfaces thereof which is a feature heretofore unobtainable in the prior art.

While the various heat exchanger constructions of this invention can be utilized for many purposes as set forth above, the finned tubular member 41 is readily adaptable for forming a frost-proof evaporator for appliances, such as refrigerators and the like.

For example, reference is now made to FIGURES 31-33 wherein the finned tube 41 of this invention is formed into an evaporator of desired design and has a heating element 106 coupled therewith, the heating element 106 being adapted to have electrical current periodically passed therethrough to cause the heating element 106 to heat the finned tube 41 to eliminate frost thereon in a conventional defrosting manner.

In particular, the heating element 106 can be coupled to the finned tube 41 by suitable clips 107 in the manner illustrated in FIGURE 31.

If desired, the finned tube 41 can have outwardly directed flanges 108 integrally extruded with the blank 40 as illustrated in FIGURE 32 whereby the integral flanges 108 can be utilized to hold the heating element 106 to the finned tube 41 by either being deformed around the heating element 106 or by having the heating element 106 snap-fitted between the preformed flanges 108.

Alternately, the heating element 106 can be passed directly through the finned tube 41 in the manner illustrated in FIGURE 33.

While the apparatus 45 of this invention has been previously described as having the fins 46 drawn, ironed and stretched by the cooperating sides 53 of the gear teeth 52 of the gear means 47 and 48, it has been found that the fiat sides 54 of the gear teeth 52 of the gear means 47 and 48 can cooperate together to form the fins 46 on the blank 40 by shearing, drawing, stretching and ironing the flanges 42 of the blank 40 in a manner now to be described.

For example, reference is now made to FIGURE 34 wherein the gear means 47 and 48 are substantially the same as the gear means 47 and 48 of FIGURE 8 except that the blank 40 is passed there'between in such a manner that the meshing gear teeth 52 shear, draw, stretch and iron the flange 42 in an upward direction to form the fins 46 between the cooperating straight surfaces 54 of the gear teeth 52. It has been found that in the embodiment of FIGURE 34, increasing the offset relation of the gears 47 and 48 increases the interference therebetween to increase the surface areas of the fins 46 over the surface areas of the parts of the flange 42 from which the respective fins 46 are made. In addition, this increased interference, and, thus, increased surfaces of the fins 46, can be further enhanced by providing a slight radius 109 on the ends of the sides 54 of the gear teeth 52 of the gear means 47 and 48 in the manner illustrated in FIGURE 34.

While the blank 40 has been previously described as being extruded, it is to be understood that the blank 40 could be made by other methods.

For example, the blank 40 could be formed by securing two flat sheets together with a longitudinal unsecured area therebetween which can be subsequently expanded to form the tubular portion 41, such as in the United States patents to Long, Number 2,662,273, and to Grenell, Number 2,690,002, while leaving the integral flanges, similar to flanges 42, which can be subsequently formed into the fins 46 by the methods previously described.

Therefore, it can be seen that not only does this invention provide an improved heat exchanger construction or the like, but also this invention provides improved methods and apparatus for making such a heat exchanger construction or the like.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims which follow.

What is claimed is:

1. A heat exchanger comprising a hollow tubular member having outwardly directed flange means integrally interconinected to the outer peripheral surface of said member, said flange means defining a fin having the base there- 'of substantially parallel with the longitudinal axis of said tubular member and having the remainder thereof disposed at an angle relative to said axis, said remainder of said fin being oppositely curved at the top and bottom ends thereof whereby said fin provides turbulence to fluid flow passing transversely relative to said longitudinal axis.

2. A heat exchanger comprising a hollow tubular member having an outwardly directed flange integrally interconnected to the outer peripheral surface of said member, said flange being divided into a plurality of fins each having the base thereof substantially parallel with the longitudinal axis of said tubular member and having the remainder thereof disposed at an angle relative to said axis, said remainder of each said fin being oppositely curved at the top and bottom ends thereof whereby each said fin provides turbulence to fluid flow passing transversely to said longitudinal axis.

3. A heat exchanger as set forth in claim 2 wherein each fin is integrally interconnected to said member by gussetlike portions on opposite sides of said fin.

4. A heat exchanger as set forth in claim 2 wherein said member has more than one flange radiating therefrom and divided into said fins.

5. A heat exchanger comprising a hollow tubular member having an outwardly directed flange integrally interconnected to the outer peripheral surface of said member and having an outer edge, said flange being divided into a plurality of fins each having a base thereof substantially 1 1' parallel with the longitudinal axis of said tubular memher and having the remainder thereof disposed at an angle relative to said axis, said remainder of each said fin being oppositely curved at the top and bottom ends thereof whereby each said fin provides turbulence to fluid flow passing transversely relative to said longitudinal axis.

6. A heat exchanger as set forth in claim 5 wherein said fins are all disposed at the same angle relative to said longitudinal axis.

- 7. A method for making a heat exchanger comprising the steps of providing a hollow tubular member having outwardly directed flange means integrally interconnected to the outer peripheral surface of said member, and drawing, ironing and shaping said flange means to provide a fin having a surface area substantially increased over the surface area of said flange means from which said fin is formed, said last-named step causing said fin to have a base thereof substantially parallel with the longitudinal axis of said tubular member and have the remainder thereof disposed at an angle relative to said axis with said remainder of said fin being oppositely curved at the top and bottom ends thereof whereby said fin provides turbulence to fluid flow passing transversely relative to said longitudinal axis.

8. A method as set forth in claim 7 wherein said surface area of said fin has been increased at least over the original surface area of said flange means.

9. A method for making a heat exchanger comprising the steps of providing a hollow tubular member having an outwardly directed flange integrally interconnected to the outer peripheral surface-of said member, dividing said flange into a plurality of fins, and drawing, ironing and shaping each fin so that the surface area thereof is substantially increased over the surface area of the part of said flange from which the respective fin is formed, said-lastnamed step causing each said fin to have a base thereof substantially parallel with the longitudinal axis of said tubular member and have the remainder thereof disposed at an angle relative to said axis with said remainder of each fin being oppositely curved at the top and bottom ends thereof whereby said fins provide turbulence to fluid flow passing transversely relative to said longitudinal axis. 9

10. A method as set-forth in claim 9 wherein said step of providing said member includes the step of extruding said member with said flange. i

11. A method as set forth in claim 9 wherein said dividing step includes the step of passing said flange longitudinally through the nip of a pair of meshing gear means.

said'flange with a uniform thickness throughout its width.

15. A method as set forth in claim 9 wherein said step of providing said member includes the step of providing said flange with a .tapering thickness throughout its width.

16. A method for making a heat exchanger comprising the steps of providing a hollow tubular member having an outwardly directed flange integrally interconnected to the outer peripheral surface of said member and having an outer edge, dividing said flange into a plurality of fins, and drawing, ironing and shaping each fin so that it is disposed at an angle relative to the longitudinal axis of said member and has the surface area thereof substantially increased over the surface area of the part of said flange from which the respective fin is formed, said fins extending inwardly from said outer edge toward said tubular member, said last-named step causing each fin to have a base thereof substantially parallel with the longitudinal axis of said tubular member and have the remainder thereof disposed at an angle relative to said axis with said remainder of each fin being oppositely curved at the top and bottom ends thereof whereby said fins provide turbulence to fluid flow passing transversely relative to said longitudinal axis.

17. A method as set forth in claim 16 wherein said surface area of each fin has been increased at least 20% over the original surface area of said part of said flange from which said fin is formed.

'18. A method as set forth in claim 16 wherein said dividing, drawing, ironing and shaping steps are provided substantially simultaneously by passing said flange through the nip of a pair of cooperating and meshing gear members.

19. A method as set forth in claim 16 wherein said dividing step forms said fins in such a manner that all of said fins are disposed at the same angle relative to said longitudinal axis.

References Cited by the Examiner UNITED STATES PATENTS JOHN F. CAMPBELL, Primary Examiner.

J. D. HOBART, Assistant Examiner. 

1. A HEAT EXCHANGER COMPRISING A HOLLOW TUBULAR MEMBER HAVING OUTWARDLY DIRECTED FLANGE MEANS INTEGRALLY INTERCONNECTED TO THE OUTER PERIPHERAL SURFACE OF SAID MEMBER, SAID FLANGE MEANS DEFINING A FIN HAVING THE BASE THEREOF SUBSTANTIALLY PARALLEL WITH THE LONGITUDINAL AXIS OF SAID TUBULAR MEMBER AND HAVING THE REMAINDER THEREOF DISPOSED AT AN ANGLE RELATIVE TO SAID AXIS, SAID REMAINDER OF SAID FIN BEING OPPOSITELY CURVED AT THE TOP AND BOTTOM ENDS THEREOF WHEREBY SAID FIN PROVIDES TURBULENCE TO FLUID FLOW PASSING TRANSVERSELY RELATIVE TO SAID LONGITUDINAL AXIS. 